Wednesday afternoon weather briefing Update from Jeff:
Significant storm system to affect the region Friday and Saturday.
Widespread heavy rainfall likely with increasing threat for flooding.
There have been no significant changes to the forecast reasoning today with a strong storm system expected to impact the areas starting as early as late Thursday afternoon with scattered showers building to more significant rainfall on Friday and Friday night. Extremely moist profiles remain in play for the Friday afternoon into early Saturday morning period with near maximum forecasted PW values for early December and a fairly deep warm and saturated profile over the area which will help to maximize rainfall rates and rainfall production. WPC has upgraded a large part of the area now into a slight risk for heavy rainfall and flash flooding and a portion of the area into a moderate risk (see graphic below).
There have been now significant changes today with expected rainfall amounts with widespread amounts of 2-5 inches likely and isolated totals up to 8 inches or possibly even slightly higher. Rainfall of this magnitude will generate significant run-off in area watersheds given the already wet conditions that area in place. Concern is growing that the areas along and NW of US 59 will see the heaviest rainfall especially the San Jacinto River basin.
Current rainfall projections, if they verify, indicate that flooding would be possible along the West Fork of the San Jacinto River, Peach Creek, Caney Creek.
Would expect significant rises…potentially to flood stage or above…on several other watersheds including the East Fork of the San Jacinto River, Cypress Creek, Cedar Bayou, Spring Creek, Little Cypress Creek, Willow Creek, Halls Bayou, Hunting Bayou, Armand Bayou, Keegans Bayou, South Mayde Creek.
Rainfall intensities in short duration will determine how watersheds such as Brays, White Oak, Buffalo, Greens, Clear Creek respond.
Addicks/Barker: Reservoirs are not holding any water and gates are currently passing normal flows. Gates will be closed once rainfall begins.
Lake Conroe: no pre-releases will be made as this would fill the downstream river ahead of the incoming rainfall
Lake Houston: The City of Houston is monitoring forecasts and will likely lower Lake Houston up to 18 inches
Forecasted Rainfall Amounts (most of this will fall Friday and Friday night):
WPC Excessive Rainfall Outlook (Friday-Saturday):
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey
Member: National Weather Association